Three-Part Review: HeadAmp Pico & RSA Predator

This is #6 (of 6) of my continued Loaner Program, for my very recently acquired HeadAmp Pico and RSA Predator. Of course everyone wants to know how these two units sound and how they compare to each other, right? Well, for the next month I'll let just 3 other people have at both of these so they can share their impressions, so I don't have to.

This thread is the repository for reviews (and pictures) of the components by each person.

Background
Mileage on Predator, Pico as of receive from ASR
~20hours on Pico
~40hours on Predator
(I believe in burn in, but I won’t get to keep it long enough)

Those who are looking for something black and white conclusive: “one amp is better than the other” it’s unrealistic and you won’t find it here. As I mentioned in my initial impression, these 2 amps sound different. Both are colored IMO.

The 701 is too new for me; therefore, I didn’t use it other than to check for obvious synergies or incompatibility (I actually sold it during the loan period). My analysis of the Pico is a little different due to my experience with the Headamp desktop line; it was extremely difficult for me to review without expecting it to be a battery powered GLite. This is the first time I ever heard an RSA product so I had an easier time describing it. It’s all very subtle of course.
I don’t have any affiliation with the companies, I was loaned the equipment by a very generous and trusting Head-Fier (ASR). I own(ed) both Headamp and RSA products at one point or another. I am more familiar with Headamp than RSA. I don’t own any kind of the amp/DAC being reviewed nor do I intend to purchase these products after this review…I still strongly prefer my balanced desktop setup. I was not blown away by either amp/DAC, and most shouldn’t expect to be. Differences are subtle, and during the last week of review I was straining to find more things to write about. I am honestly sick of listening for differences…I just want to enjoy the music at this point.
Both are very good amps, you can’t go wrong with either depending on what sound you want. For ~500 these will give a $1-2000 setup a really good run for the money. I think the Pico sounds really good with the HD600 and the Predator should synergize with both 600/650. I think the key is to feed it with a very high quality source/lossless music and keep the volume up. Don’t forget to keep the amps charged.
I am used to listening to my gear balanced. This is some of the best single ended stuff I have heard in a while. Most of the review was written before i even heard my Apache.

PREDATOR
Ergonomics/Finish/Components/Presentation:

Very nice brushed texture and silk screening. Interesting glowing power switch. Maybe it was intentional to illuminate the volume switch in the dark. However ergonomic suffers since it’s close to volume knob that is a little bit too small for even my dexterous fingers. Size is slightly longer than the Pico, but otherwise pretty close.

I can say much about the key components because they’re obviously obscured on purpose. Single cell LIPO (I estimate ~950mAH). There are two single circuit OpAmps; one for each channel.

Noise/Volume/Gain:

Substantially silent noise floor as tested via IEM. I used K701 and HD650 on HIGH gain (3 selectable gains). More than enough gain for the 701 or 650. Volume control works well from 0-100. Both amps definitely have enough gain to make noise in these upper mid efficiency/impedance headphones.

Obvious qualities:
Cold* definitely not warm **some people disagree. I think my Apache is warm, the pico is very warm, But not this thing.
Lots of details/analytical
Airy, open window to the music, but still a window
Aggressive attack
Engaging
Dynamic, but lean sounding compared to Pico
Less body compared to Pico
Has Snap to it
Punchy Bass

Other comments:

Based on reviews that I have read, the amp section sounds like it might be similar to the Hornet.

The Predator changed a lot in the time that I had it. That huge capacitor under the hood must have something to do with it. Due to this phenomenon, I removed a lot of descriptive material that I wanted to put down here so that I wouldn’t be contradicting myself.

The low levels of congestion in the Predator remind me of my Apache. However, it is not warm like the Apache.

Air and space that separates the elements of music with this amp. Allows good focus and imaging.

Weaknesses:
I think the highs got a little strident
Might be fatiguing for some people/headphones
Lacks body to music

PICO
Ergonomics/Finish/Components/Presentation:

I won’t even talk about size because it’s small enough and I wouldn’t want anything smaller. Very nice piano black finish that gets fingerprints easily. A small knob that can be turned easily. On/off switch built into volume pot. Perfect ergonomics IMO for something this small. The Pico has a useful charge status LED.

2cell 500mAH LIPO with modular power supply/charger board. I suspect that separate cells are used for +/-3.7v and the battery is ‘balance charged/matched’. I believe the Pico has a battery protection circuit to prevent over-discharge. Slow charge is good to prolong the life of lithium batteries.
Wolfson WM8740 24Bit 192khz DAC
AD8397 OpAmp (Dual circuit)

Noise/Volume/Gain:

Substantially silent noise floor as tested via IEM. I use K701 and HD650 on the high gain (2 selectable gains). Plenty of gain for the 701 or 650. Volume pot doesn’t seem to do anything before 9 o’clock (non linearity). Having the power switch in the Pot might have something to do with this. Both amps definitely have enough gain to make noise in these upper mid efficiency/impedance headphones.

Obvious qualities:
Full bodied, lush sound
Smooth
Warm, sweetened
Enveloping
Easy on the ears
Deeper bass extension compared to predator.
The Pico is not as neutral as headamp’s desktop line.
Overall, I think Pico gives more weight across the frequency range than Predator.
I feel a slight congestion and stuffiness in the music with this amp compared to the Predator, especially at low volume levels.

Other comments:

The Pico’s battery life is shorter than the Predator.

I detect veil and some warmness to the Pico. The Gilmore Lite had this too, but Much less. It disappears 98% with the GS1 and pretty much completely with the GSX. The warmness is unlike the desktop lines for Headamp; those are very neutral in comparison.

Sometimes I feel this amp is overly warm. To the point where it’s congested and stuffy.

Pico sounds very good with the volume at a higher level. Anyway, the Pico has the sound signature of a very high end amp.

I like the way the Pico is constructed in stacked design. It looks easier to service the battery. If it could roll opamps that would be cool.

First, I want to thank ASR for including me in this loaner program. Since I live at least five hours from the rest of the world, I don’t get the chance to hear gear unless I buy it. So I have really enjoyed getting the chance to hear both of these great amps. This is my first attempt at writing any sort of review, so I hope my descriptions of what I heard are helpful.

My first comment when I took these out of their boxes was “damn” these are tiny! Even though I had owned a Hornet at one time, I was blown away at how small these DAC/amp combos were. The build quality of both amps is superb. I did like the extra charging indicator LED on the Pico. And the piano gloss finish is a nice touch. Other than that I felt that they were both on equal footing in build quality and ease of use department. I put about 20 hours on each amp during the 10 days I had them.

Gear
I listened from my Sony Vaio laptop using JRiver’s Media Jukebox 12. Most of my comparing was done with RS1’s, but I did listen with the rest of the cans I own enough to see that neither amp had any trouble driving any of the headphones I own. I was having trouble with my IEM’s so those unfortunately did not get much attention. I spent quite a bit of time comparing the DAC section of both the Predator and the Pico to my MicroDAC (with an upgraded opa 2134 chip) and to my Stello DA100.

Predator VS Pico
Naming a winner between these two will come down to personal choice and headphone compatibility. Neither is heads above the other, but they do sound very different. I was a little worried before getting both amps that I wouldn’t be able to hear a difference & would have nothing to write Luckily that wasn’t the case. In fact I was able to name the amp 10/12 times while my hubby changed them behind my back!

The Predator was more aggressive and punchier sounding. There is plenty of air and space between the instruments. I did not have a sense of congestion with it at all. The highs were a bit too bright for my tastes even with darker sounding cans like the DB’s. The Pico has a bit darker and more full or rich sound. The soundstage sounded a little wider to me, but this might have been my ears reacting to the more aggressive and forward sound of the Predator. The bass is just a little more weighty and extended with the Pico than with the Predator. The high end is not quite as bright. If I had to choose only one of them I would probably go with the Pico. I prefer the smoother, richer sound even at the expense of the more aggressive punchier sound of the Predator.

MicroDAC & Stello vs. Predator & Pico

This was an easy win for the MicroDAC over both the internal DACs in the Pico & Predator. I spent a couple of days switching between these to be sure of what I was hearing. I listened for an hour or so at a time, then I made quicker switches listening to just small segments of music repeatedly. I switched between the native DAC’s of both the predator & the Pico & the MD & then leaving the MD I switched between the amp sections of the Predator & Pico. There was much more separation between instruments with the MicroDAC which gives a sense of clarity that just sounds better to me. Now keep in mind that my MicroDAC has been upgraded. In fact, I find it a very close match to my Stello. I heard basically the same differences between the Stello and the Pico & predator as I did with the MD. Though I think the Stello has the advantage by a hair. The bass was quicker and more able to keep up with fast passages.

When I switched between the Pico & Predator’s amp sections using the MicroDAC to feed them, the difference between the two amps was most apparent. The amp section of the Pico was much more pleasing to my ears than the Predator. The Predator sounded thin in comparison to the Pico. This seemed more exaggerated to me than when comparing both amps with their own DACs in play. I had my husband switch between the amps without seeing what he was doing. I was able to pick out the correct amp 9/10 times. This made me feel a little better that I was really hearing what I thought I was! Both the Predator & Pico outdid my Pint!

If I were going to buy one of these it would probably be the Pico – but not by a long shot. The differences are not subtle but both are very enjoyable to listen to. I wish that they could have a mini optical in so that I could use my IRiver HP140 with them. But I guess we can’t have it all The battery life on both of them was just excellent. I listened off & on all day for both weekends that I had them & neither of them ever ran out of steam.

The discussion of the amps is coming soon. Here are some photos comparing the Predator and the Pico to other amps. From left to right: Xin SuperMini IV, Predator, Pico, SR-71, Mini-Box E, Xin SuperMicro IV, and the stack is self-explanatory.

The discussion of the amps is coming soon. Here are some photos comparing the Predator and the Pico to other amps. From left to right: Xin SuperMini IV, Predator, Pico, SR-71, Mini-Box E, Xin SuperMicro IV, and the stack is self-explanatory.